ES-7652 Rev.21

27HU-B

Head-mounted Two-wire Signal Conditioners
27-UNIT

2-WIRE UNIVERSAL TEMPERATURE TRANSMITTER

(HART communication, outdoor enclosure, explosion-proof)
Functions & Features
• Universal input: DC mV, T/C, RTD and resistance
• High accuracy
• HART communication
• Explosion-proof approval
• Suitable for Functional Safety applications up to SIL2
• Programming via hand-held communicator or via PC
• A wide variety of T/C and RTD types
• User’s temperature table can be used
• Self diagnostics
• Ultra-low temp. drift option (20 ppm/°C typ.)
• Stainless steel enclosure optional

MODEL: 27HU–B–[1][2][3][4][5][6][7]

ORDERING INFORMATION

• Code number: 27HU-B-[1][2][3][4][5][6][7]
Specify a code from below for each of [1] through [7].
  (e.g. 27HU-B-0L1T01/S).
Use Ordering Information Sheet (No. ESU-7652). Factory standard setting will be used if not otherwise specified.
Specify the country in which the product is to be used with the Safety Approval code 4.

[1] SAFETY APPROVAL

Confirm selectable combinations of approval and wiring
conduit types in the table below.
0: None
3: FM explosion-proof
4: ATEX flameproof

[2] TEMPERATURE DRIFT

0: Standard (temp. coefficient 0.015 %/°C)
L: Ultra-low temperature drift
(temp. coefficient 0.002 %/°C typ. 0.005 %/°C max.)

[3] LED INDICATOR

0: Without
1: With (SIL not available)

[4] TERMINAL BLOCK

0: None (Output connection: Terminals on module)
T: Incorporated
(Selectable only with the LED indicator option)

[5] WIRING CONDUIT

Confirm selectable combinations of approval and wiring
conduit types in the table below.
0: G 1/2
1: 1/2 NPT
2: M20 × 1.5
3: PG 13.5

[6] MOUNTING BRACKET

0: Without
1: With

[7] OPTIONS

Enclosure Materials
Blank: Diecast aluminium enclosure
/S: Stainless steel enclosure

RELATED PRODUCTS

• USB interface Bell202 modem (model: COP-HU)
Usable in ‘non-hazardous’ area only.
• Hand-held communicator
• PC configurator software (model: 27HUCFG)
Downloadable at our web site.

PACKAGE INCLUDES...

• Mounting screws
    Bolt (M8 x 15): 4 pcs.
    Spring washer for M8: 4 pcs.
    Material: Stainless steel 304
• Mounting bracket assembly (option)
    Mounting bracket: 1 pcs.
    M10 U-bolt: 2 pcs.
    Nut for M10: 4 pcs.
    Spring washer for M10: 4 pcs.
  Material:  Stainless steel 304
  Applicable pipe: 1 1/2” min.; 2” max.
• Engineering unit label (1)

GENERAL SPECIFICATIONS

Degree of protection: NEMA 4X, IP66/IP67
Wiring conduit: See ‘Ordering information.’
Connection:
• Without terminal block and indicator: M3 screw terminal in transmitter
   (Torque: 0.5 N･m)
• Without terminal block with indicator:
  Input signal: M3 screw terminal in transmitter
  (Torque: 0.5 N･m)
  Output signal: Euro terminal
  (Applicable wire size: 0.14 to 1.5 mm2 (AWG26 to 16), stripped length: 6 mm)
• With Terminal block and indicator:
  Input signal: M3 screw terminal in transmitter
  (Torque: 0.5 N･m)
  Output signal: M3 screws in terminal block
  (Torque: 0.5 N･m)
Screw terminal
• Input signal: Nickel-plated brass
• Output signal:
  Without terminal block and indicator: Nickel-plated brass
  With terminal block and indicator: Nickel-plated steel   
Materials
Transmitter Housing: Flame-resistant resin (black)
Indicator Housing: Flame-resistant resin (black)
Enclosure material: Diecast aluminium standard; SCS14 stainless steel casting optional (equivalent to type 316); silver color,　epoxy resin coated
Isolation: Input to output to outdoor enclosure
User-configurable items:
• Input sensor type and numbers
• Number of wires (RTD & resistance)
• Input range (inverted range selectable)
• Burnout
• Output limits (Upper / Lower)
• Damping time (factory set to 0)
• Cold junction compensation (T/C; internal or external
 sensor selectable)
• Linearization
• Sensor calibration
• Output calibration
• HART communication mode
Refer to the HART setup manual or the PC configurator users manual for the detail.

HART COMMUNICATION

Protocol: HART communication protocol
HART address range: 0 – 15 (factory set to 0)
Transmission speed: 1200 bps
Digital current: Approx. 1 mAp-p when communicating
Character format: 1 Start Bit, 8 Data Bits, 1 Odd Parity Bit,
1 Stop Bit
Distance: 1.5 km (0.9 miles)
HART communication mode: Master-Slave Mode and Burst Mode (factory set to Master-Slave)
HART network mode: Point-to-Point Mode and Multi-drop Mode; automatically set to Multi-drop Mode when the address is set to other than 0.

LED INDICATOR (option)

LED: 8 mm (.3”) 7-segment, red
Number of display digits: 4
Scaling range: -1999 to 9999
Offset range: -1999 to 9999
Decimal point position: 10 –1, 10 –2, 10 –3, or no decimal point
Polarity sign: Minus (–) sign added automatically according to the computation result
Read rate: 2.5/s
Over-range warning: All segments dark except the top ones that blink with the input exceeding the display/measurable range; or the bottom ones that blink with the input below the range.
Engineering unit display: Unit label included; LED backlight provided
Engineering unit indication: Sticker label attached
DC, AC, W, ℃ , °F, V, mV, A, mA, %, kW, mW, kV, kA, psi, K, bar, barg, Nℓ/min, kvar, Mvar, var, m, mm, kg, kg/h, kPa, MPa, N·m, Nm3/h, m3/h, m3/sec, m/sec, kgf/cm2, ℓ/min, %RH, ℓ, ℓ/h, t/h, rpm, ppm, pH, Pa

INPUT SPECIFICATIONS

The input is factory set for use with K thermocouple, single input, 0 to 100°C, internal CJC sensor.
See Table 1 for the available input type, the minimum span and the maximum range.
■ DC mV (dual input available)
Input resistance: ≥ 1 MΩ
■ Thermocouple (dual input available)
Input resistance: ≥ 1 MΩ
Burnout sensing: 33 μA
External CJC sensor type: Pt 100
■ RTD (2-wire, 3-wire or 4-wire)
Input resistance: ≥ 1 MΩ
Excitation: 0.2 mA
Allowable leadwire resistance: Max. 10 Ω per wire
■ Resistance (2-wire, 3-wire or 4-wire)
Input resistance: ≥ 1 MΩ
Excitation: 0.2 mA
Allowable leadwire resistance: Max. 10 Ω per wire

OUTPUT SPECIFICATIONS

Output range: 4 – 20 mA DC
Operational range: 3.75 – 23 mA
Load resistance vs. supply voltage:
Load Resistance (Ω) = (Supply Voltage (V) – 8 (V)*) ÷
0.023 (A)    (including leadwire resistance)
*12 (V) with LED indicator option.
Burnout: 3.75 – 3.8 mA or 21.5 – 23 mA
(factory set to 23 mA)
Upper output limit proportional to the input:
20 – 21.5 mA (factory set to 21.5 mA)
Lower output limit proportional to the input:
3.8 – 4 mA (factory set to 3.8 mA)
Update time: 440 msec. (660 msec. with dual input)
Output characteristics for dual input:
Average or Differential selectable

INSTALLATION

Supply voltage
Non-approved: 8 – 35 V DC (without LED indicator)
12 – 39 V DC (with LED indicator)
ATEX & FM: 8 – 32 V DC (without LED indicator)
12 – 32 V DC (with LED indicator)
Operating temperature
Non-approved: -40 to +85°C (-40 to +185°F)
ATEX & FM: T5, -40 to +80°C (-40 to +176°F)
T6, -40 to +70°C (-40 to +158°F)
Weight: 
· Unit
  Approx. 1.3 kg (2.9 lb), aluminium
  Approx. 4.0 kg (8.8 lb), stainless steel
· Mounting bracket set (option)
  Approx. 0.78 kg (1.72 lb)

PERFORMANCE

Accuracy: See Table 1.
Display accuracy: ±0.01 mA
(Refer to 'how to calculate accuracy against scale'.)
Cold junction compensation accuracy: ±0.5°C (±0.9°F) with internal CJC sensor
LED indicator temp. coefficient: ±0.015 %/°C
Response time: ≤ 2 sec. (0 – 90 %) with damping time
set to 0 and when not communicating via HART.
Supply voltage effect: ±0.005 % of span/V
Insulation resistance: ≥ 100 MΩ with 500 V DC
Dielectric strength: 1500 V AC @1 minute
(input to output to outdoor enclosure)
Safety integrity level according to IEC 61508: Suitable for use in a safety instrumented system up to SIL2 (together with sensor) if appropriate safety instructions are observed. Consult us.

HOW TO CALCULATE ACCURACY AGAINST SCALE

Example: 4 – 20 mA input, Scale 0 – 100
Accuracy = 0.01 mA ÷ (20 – 4)mA × 100 = 0.063 %
Display Error = (100 – 0) × 0.063 % = ±0.063 digits

STANDARDS & APPROVALS

EU conformity:
ATEX Directive 
  Ex db EN 60079-1
EMC Directive 
  EMI EN 61000-6-4
  EMS EN 61000-6-2
RoHS Directive
Safety approval:
FM: Explosion-proof and Dust-ignition proof
  Class I, Division 1, Groups B, C and D
  Class II, Division 1, Groups E, F and G
  Class III, Division 1
  T5 and T6
  (Class 3615)

INDICATOR TOP VIEW (option)

INPUT TYPE, RANGE & ACCURACY

EXTERNAL DIMENSIONS unit: mm [inch]

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM